the three you mentioned (Burt, Bob & Joan) constitute an impressive trinity of SoCal koi
cognoscente! Best listen to 'em.
You also might be interested in a current thread on NI's KoiMag.com:
Re: No chance...he's far more koi knowledgeable than all of us together -
James P 12/5/2005, 12:52 am
It's located at:
http://members4.boardhost.com/koimag/
wherein JR and Lee Aronfield bat that question around with great gusto.
Personally, I'm with Antonio. I think that with our climate it's OK to feed several times a week, except during the coldest part of the winter -- and especially so when
tosai are in the pond.